It is known to construct tubular members for vehicles such as automotive vehicles. The tubular members are typically roll-formed and/or extruded from steel, aluminum, or magnesium and have a constant wall thickness. However, it is occasionally desirable to have a tubular member that has an increased stiffness, wherein the stiffness is increased away from the ends of the tubular member.
It is also known that rollformers or tailored tube producers have made steel tubular members with increased stiffness around the perimeter of the tubular member. To increase the stiffness, strips of metal have been welded together axially prior to joining the strips into a tubular form. However, these tubular members are costly due to the extra material and labor involved.
It is known to hydroform tubular components or members. Hydroformed tubular members are becoming increasingly popular in automotive body structural applications. During vehicle body manufacturing, many of the hydroformed tubular members are used in vehicle body and chassis applications. However, vehicle strength, stiffness, and/or impactworthiness often necessitate the need for local areas of structural reinforcement to meet their design goals.
As a result, it is desirable to provide an apparatus for locally expanding a tubular member or blank to achieve a desirable stiffness where needed for a structural member of a vehicle. It is also desirable to provide a hydroformed tubular member having a local expansion away from the ends of the tubular member for a structural member of a vehicle. It is further desirable to provide a method for locally expanding a tubular member away from the ends of the tubular member. Therefore, there is a need in the art to provide a new cost effective apparatus and method that meets at least one of these desires.